Utility lamp

Abstract

A utility lamp ( 1 ) comprises a curved reflector ( 2 ) having a spherically curved surface. An array of LEDs ( 3 ) is arranged in an electrical circuit on a thin substrate mounted via thermally conductive epoxy on a thermally-conductive base ( 4 ), which in turn forms an integral part of the reflector ( 2 ). The LEDs are mounted for efficient heat transfer by conduction to the reflector ( 2 ). The reflector ( 2 ) thus operates as both a light reflector and as a radiative heat sink. The heat radiating properties of the reflector are enhanced by integral fins ( 7 ) extending in the radial direction around the periphery of the reflector ( 2 ). The reflector ( 2 ) is of integral aluminium construction.

The invention claimed is: 
     
       1. A utility lamp comprising:
 a group of at least one light emitting diode; 
 a reflector comprising;
 a base, 
 a wall having an internal light-reflecting surface, and thermal dissipation fins 
 
 the diode group being mounted on a thermally-conductive circuit board which is secured to the reflector base:
 some emitted light reflects from the internal surface of the reflector wall, and 
 heat from the diode group is conducted into the reflector, and the reflector radiates this heat from its exposed surfaces; 
 
 wherein the reflector is of greater cross-sectional area at the base than at the wall; 
 wherein the fins extend from an external surface of the reflector wall, opposed to the internal light-reflecting surface; 
 wherein the circuit board comprises a metal layer; and 
 wherein each diode is of the surface mount type, the anode and cathode of which are soldered to metal tracks which have a thermal path to the reflector. 
 
     
     
       2. The lamp as claimed in  claim 1 , wherein the circuit board is secured to the reflector base by a thermally-conductive bonding agent. 
     
     
       3. The lamp as claimed in  claim 1 , wherein the metal layer underlies a multi-layer circuit board structure. 
     
     
       4. The lamp as claimed in  claim 1 , further comprising a diode drive circuit mounted in a housing on the reflector base on a side opposed to that of the diode group, the housing being in thermal contact with the reflector. 
     
     
       5. The lamp as claimed in  claim 4 , wherein an electrical connector fixture is secured to the housing. 
     
     
       6. The utility lamp as claimed in  claim 1 , wherein the reflector shape is spherical. 
     
     
       7. The utility lamp as claimed in  claim 1 , wherein the reflector shape is parabolic. 
     
     
       8. The utility lamp as claimed in  claim 1 , wherein the reflector shape is hyperbolic. 
     
     
       9. The utility lamp as claimed in  claim 1 , wherein the reflector shape is ellipsoidal. 
     
     
       10. The utility lamp as claimed in  claim 1 , further comprising an optical element mounted over the diode group. 
     
     
       11. The utility lamp as claimed in  claim 1 , further comprising an optical element mounted over the diode group; and wherein the optical element comprises an internal reflector for reflecting light from the diode group onto the reflector. 
     
     
       12. The utility lamp as claimed in  claim 11 , wherein the internal reflector is of conical or frusto-conical shape. 
     
     
       13. The utility lamp as claimed in  claim 11 , wherein the internal reflector comprises a central aperture for narrow-angle light and a lens aligned with the aperture for focusing said light. 
     
     
       14. The utility lamp as claimed in  claim 1 , wherein the fins have an annular configuration, extending around the reflector. 
     
     
       15. A utility lamp comprising:
 a group of at least one light emitting diode; 
 a reflector comprising;
 a base, 
 a wall having an internal light-reflecting surface, and thermal dissipation fins 
 
 the diode group being mounted on a thermally-conductive circuit board which is secured to the reflector base:
 some emitted light reflects from the internal surface of the reflector wall, and 
 heat from the diode group is conducted into the reflector, and the reflector radiates this heat from its exposed surfaces; 
 
 wherein the reflector is of greater cross-sectional area at the base than at the wall; 
 wherein the fins extend from an external surface of the reflector wall, opposed to the internal light-reflecting surface; and 
 wherein the lamp further comprises a diode drive circuit mounted in a housing on the reflector base on a side opposed to that of the diode group, the housing being in thermal contact with the reflector. 
 
     
     
       16. The lamp as claimed in  claim 15 , wherein an electrical connector fixture is secured to the housing. 
     
     
       17. A utility lamp comprising:
 a group of at least one light emitting diode; 
 a reflector comprising;
 a base, 
 a wall having an internal light-reflecting surface, and thermal dissipation fins 
 
 the diode group being mounted on a thermally-conductive circuit board which is secured to the reflector base:
 some emitted light reflects from the internal surface of the reflector wall, and 
 heat from the diode group is conducted into the reflector, and the reflector radiates this heat from its exposed surfaces; 
 
 wherein the reflector is of greater cross-sectional area at the base than at the wall; 
 wherein the fins extend from an external surface of the reflector wall, opposed to the internal light-reflecting surface; 
 wherein the lamp further comprises an optical element mounted over the diode group; 
 wherein the optical element comprises an internal reflector for reflecting light from the diode group onto the reflector; and 
 wherein the internal reflector comprises a central aperture for narrow-angle light and a lens aligned with the aperture for focusing said light.